|
DER/CHP Analysis
ORNL developed the BCHP Screening Tool for evaluations of combined cooling, heating, and power in commercial buildings.
Introduction
The economic evaluation of proposed installations of combined cooling, heating, and power (CHP) systems requires calculations that consider building heating, cooling, hot water, and electrical loads, the costs of power and natural gas (including block rates, demand and standby charges, and ratchets), and the simulated performance of generators, chillers, boilers, and water heaters. Ideally this is done on an hour-by-hour basis so thermal loads and electrical generation can be matched in time and so energy cost savings can be calculated correctly for time-of-day rates. Comparisons with non-CHP systems are customarily made in terms of life cycle cost, net present value, and simple payback.
Summary
The BCHP Screening Tool performs these functions, smoothly executing DOE2.1e in the background to determine building loads from general parameters provided by the user, combine thermal and electrical loads with operating parameters for generators and HVAC equipment to determine energy requirements for part load and off-design operation of gensets and chillers, and to determine estimated annual electric and natural gas costs using algorithms from a database of gas and electric utility rates.
Results are returned to the user in tabular and graphical forms with displays of annual and monthly energy use, hourly equipment inputs and outputs for a typical weather year, and simultaneous comparisons of up to 25 CHP configurations with a non-CHP baseline system. Users can select locations from 239 cities in the U.S. and utility rates from over 100 gas and 100 electric utilities throughout the country. Some familiarity with HVAC and power generating equipment is required, but the user does not need to have any background in using DOE2 in order to use the BCHP Screening Tool successfully.
Key features of The BCHP Screening Tool are displayed in “New Features of the BCHP Screening Tool” and the program itself is available free of charge from the link below. ORNL developed the BCHP Screening Tool for evaluations of combined cooling, heating, and power in commercial buildings.
(download program; 30MB)
|
|
